This invention relates to improvements in processes and in machines, for splicing together running webs of paper or the like, e.g., webs or strips of paper or other wrapping material for use in the making of plain or filter cigarettes, cigars, cigarillos and/or other rod-shaped smokers"" products. More particularly, the invention relates to improvements in processes and machines for splicing trailing ends of lengthwise moving expiring webs or strips of paper or the like to leading ends of lengthwise advancing fresh webs in such a way that the leading and trailing ends need not be adhesively and/or thermally secured to each other. Still more particularly, the instant invention relates to improvements in processes or methods and in machines for securing the leading and trailing ends of pairs of running webs or strips of deformable material to each other while the two ends advance lengthwise, in the same direction, adjacent one another, at or close to identical speeds and are pressed against each other. Splicing undertakings of such character include folding and knurling.
Processes and apparatus or machines for splicing the leading ends of fresh running webs to the trailing ends of expiring running webs are resorted to, among other undertakings, in the tobacco processing industry, e.g., to connect the leader of a rotating fresh bobbin or reel of convoluted cigarette paper or other strip- or web-shaped deformable wrapping or confining material to the trailing end of a rotating nearly expired or exhausted bobbin or reel of wrapping material in such a way that the delivery of wrapping material to the wrapping station of a cigarette maker or another web processing or consuming machine need not be interrupted or decelerated. This greatly reduces the number of rejects and enhances the output, especially in certain modern high-speed web processing machines which are designed to turn out well in excess of 10,000 rod-shaped smokers"" products or the like per minute.
Presently known methods or processes and machines or apparatus of the above outlined character are disclosed, for example, in the assignee""s German patent No. 693 00 282, German Utility Model No. 1 995 937 and published German patent applications Serial Nos. 1 532 203 and 1 532 204. U.S. Pat. No. 3,089,661 (granted May 14, 1963 to Malcolm E. Phillips, Jr. et al.) discloses an automatic cigarette paper splicer wherein a fresh convoluted cigarette paper web is accelerated to the speed of a running (expiring) cigarette paper web by taking into consideration the mass of the supply (such as a bobbin) of fresh convoluted web, the speed of the expiring bobbin of convoluted web and the tensional strength of the webs. Two rotary splicing sectors are provided to connect the leading end to the trailing end when the speed of the leading end matches that of the trailing end as well as the peripheral speeds of the two sectors. The splicing involves or can involve one revolution of each sector about its respective axis. The final steps of the Patented ed splicing operation include the severing of those (foremost and rearmost) ends of the spliced-together webs which respectively extend forwardly and rearwardly of the finished splice. Such final steps are carried out by resorting to knives which are actuated in dependency upon the positions of the splicing sectors.
An advantage of the automatic splicer which is disclosed in the U.S. Pat. No. 3,089,661 to Phillips et al. is that the operation of the web processing apparatus or machine (e.g., a machine which confines a continuous rod-like filler or natural, substitute or reconstituted tobacco in a continuous web of cigarette paper or the like) need not be interrupted when the supply of a reel of convoluted web-like or strip-like wrapping material is exhausted, i.e., that the splicing operation can be carried out while the expiring web and the fresh web are being moved at the prescribed speed of the wrapping material entering the processing machine.
Another presently known mode of splicing the leader of a fresh web to the trailing end of a moving expiring web in a cigarette maker is to resort to a magazine which is designed to temporarily store a length of the expiring web. Such proposals are not entirely satisfactory because the magazine takes up a substantial amount of space in a cigarette making or like plant wherein hundreds of wrapping machines are confined in a common hall, i.e., wherein the hall must accommodate a discrete magazine for each wrapping machine.
An object of the instant invention is to provide a novel and improved process for splicing the running trailing end of an expiring web of paper or the like to the running leader of a fresh web in a novel and improved manner, particularly or at least as concerns the appearance, the uniformity and the strength of the splices.
Another object of our present invention is to provide a process which can be practiced with advantage in connection with the making of wrapped tobacco products and which can be carried out without resorting to magazines or similar bulky facilities for temporary storage of looped and/or otherwise deformed webs of wrapping material.
A further object of the invention is to provide a novel and improved machine or apparatus for the practice of the above outlined process.
An additional object of our invention is to provide the machine with a novel and improved mechanism for making a pressure splice between the continuously advancing trailing end of an expiring web of paper or the like and a continuously advancing leading end of a fresh web.
Still another object of this invention is to reduce the number of rejects among the products which are obtained by draping a composite running web of paper or the like around a rod-shaped tobacco filler and/or filter material for tobacco smoke or the like.
A further object of this invention is to provide a novel and improved process as well as a novel and improved arrangement for trimming the front and/or rear ends of splices between selected portions of an expiring web and a fresh web of paper or other wrapping material.
Another object of the invention is to provide a novel and improved process and a novel and improved machine or apparatus of the above outlined character which can be incorporated into or otherwise combined with presently known processes and/or machines for wrapping commodities into and/or for otherwise associating commodities with continuous running webs of paper, plastic material or the like.
An additional object of the present invention is to provide a novel and improved system for regulating the operation of motors and/or other prime movers in a machine of the above outlined character.
Still another object of the invention is to provide a novel and improved cigarette making or other tobacco processing machine which cooperates with or embodies a machine of the above outlined character.
A further object of the invention is to provide a web splicing machine which is constructed and assembled in such a way that it allows for convenient threading of fresh webs into their prescribed path and for readily observable advancement of successive webs of paper or the like to the web processing or consuming station.
One feature of this invention resides in the provision of a process for splicing the trailing end of an expiring running web (e.g., of cigarette paper or the like) to the leading end of a fresh running web. The improved process comprises the steps of advancing the leading and trailing ends of the webs in at least substantial parallelism with and next to each other at an at least substantially identical speed along a path which is flanked by a rotary knurling surface and a rotary countersurface, and rotating the surfaces at different speeds through a majority of a plurality of revolutions. The revolutions include an n-th revolution during which the surfaces are sufficiently close to each other to splice the trailing end to the leading end in the path. Furthermore, n is greater than one.
The rotating step can include maintaining the speeds of the knurling surface and the countersurface at least close to the substantially identical speed of the webs in their path in the course of the n-th revolution. The process can be carried out in such a way that n is at least close to ten revolutions. Furthermore, the ratio of the different speeds can equal or approximate 10:11.
The process can further comprise the step of bringing one of the surfaces into contact with one of the webs in the path only in the course of the n-th revolution; such one surface can constitute the knurling surface.
The rotating step can further include rotating the surfaces at an at least substantially identical speed in the course of the n-th revolution.
The positions of the leading and trailing ends of the two webs can be selected in such a way that the rotating step entails the provision of at least one remnant which develops in the course of the n-th revolution and is of one piece with one of the webs; the improved process then preferably further includes the step of separating the at least one remnant from the spliced-together webs. Such separating step preferably includes moving the at least one remnant at a speed other than the at least substantially identical speed of the webs in their path.
If the rotating step entails the provision of a remnant of the expiring web, the separating step can include reducing the speed of the remnant below the at least substantially identical speed of the webs in their path. Such speed reducing step preferably includes braking the remnant of the expiring web.
If the rotating step entails the provision of a remnant at the fresh web and such remnant extends forwardly of the splice, the separating step preferably includes accelerating the remnant to a speed above the at least substantially identical speed of the webs in their path. Such accelerating step can be carried out during one of the stages including (a) simultaneously with the splicing of the webs to each other, and (b) subsequent to the splicing.
Another feature of the instant invention resides in the provision of a machine for splicing the trailing end of an expiring running web (e.g., a web of cigarette paper or the like) to the leading end of a fresh running web while the leading and trailing ends advance next to each other, in the same direction and at an at least substantially identical speed. The improved apparatus comprises a rotary knurling member which is adjacent one side of the path for the webs, a rotary splicing member adjacent the other side of the path for the webs at least substantially opposite the knurling member, regulatable drive means for the rotary members, and means for regulating the drive means to rotate the two members at different speeds through a majority of a plurality of revolutions including an n-th revolution during which the members are sufficiently close to each other to splice the trailing end of the expiring web to the leading end of the fresh web in the aforementioned path. In accordance with a desirable feature of the machine, the number n is greater than one (e.g., 10).
The knurling member can be provided with a peripheral knurling surface and the splicing member can be provided with a peripheral countersurface which cooperates with the knurling surface to splice the leading and trailing ends of the webs in their path to each other in the course of the n-th revolution of the aforementioned plurality of revolutions. The drive means can include means for rotating the knurling and splicing members about spaced-apart at least substantially parallel axes. At least one of the members can include a segment which is arranged to orbit about the respective axis, and the means for rotating can include a roll which is rotatable about the respective axis and has a peripheral surface bearing the segment.
Alternatively, the means for rotating the two members can include two rolls each of which is rotatable about a different one of the spaced-apart at least substantially parallel axes. The knurling member of such machine can include a first segment which is borne by one of the rolls, and the splicing member can include a second segment which is borne by the other roll. The two axes can be spaced apart from each other a distance which is required to ensure that the segments compress the webs in their path and thus splice the webs to each other only during the n-th revolution of the aforementioned plurality of revolutions.
The improved machine can be set up to splice the trailing end of an expiring web to the leading end of a fresh web in such a way that at least one of the webs includes a remnant which extends beyond the spliced-together portions of the webs in their path. Such machine preferably further comprises means for separating the remnant from the at least one web not later than upon completed splicing of the webs to each other.
The separating means can include means for tearing the remnant from the at least one web, and such tearing means can include means for changing the speed of the remnant and of the spliced-together portions of the webs relative to each other. The just described machine can be designed in such a way that each of the two members has a knurling surface, and the drive means can comprise a rotary roll for each of the two members. The rolls are rotatable about at least substantially parallel axes, and the member borne by at least one of the rolls can include a segment which is provided on the peripheral surface of the at least one roll.
If the remnant forms a rearwardly extending part of the trailing end of the expiring web, then the aforementioned speed changing means of the tearing means can include a brake which is operable by the regulating means to decelerate the remnant not later than upon the splicing of leading and trailing ends of the two webs to each other. This results in tearing of the remnant off the expiring web along the trailing edge of the splice between the two webs.
Alternatively, or in addition to the provision of a remnant which extends rearwardly of the freshly formed splice, the splicing operation can result in the provision of a remnant which forms a forwardly projecting part of the leading end of the fresh web. The speed changing means of the tearing means then includes or can include means for raising the speed of the forwardly projecting remnant relative to the spliced-together portions of the web. Such speed changing means can form part of a means (e.g., a variable-speed electric motor and a pair of rollers driven by such motor) for advancing the fresh web in the aforementioned direction.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved machine itself, however, both as to its construction and the modes of assembling, installing and operating the same, together with numerous additional important and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.